BING SWEET CHERRY LEAF NUTRITION IS AFFECTED BY ROOTSTOCK

Leaf nutrient concentration of 'Bing' sweet cherry (Prunus avium L.) w as affected by rootstock over 4 years in the Pacific Northwest. Trees on GM 79, GI 148/1, GI 195/1, and GI 196/4, which had higher yields th an Mazzard, also had lower leaf K and, excepting GM 79, lower leaf Mg concentration. Use of GI 195/1 and 196/4 resulted in lower leaf N than use of Mazzard. These higher-yielding rootstocks will require greater attention to these macronutrients, especially on infertile soil sites . Micronutrient nutrition was little affected by rootstocks, which ten ded to have the low leaf Zn concentrations typical of irrigated Pacifi c Northwest orchards. GM 9 and GM 61/1 rootstocks were more dwarfing t han Mazzard, with GM 9 leaves having lower K, but higher P, Mg, and Mn concentrations. GM 61/1 had lower leaf concentrations of most nutrien ts relative to Mazzard.